'64 ST400 Transmission Tag

[Guest dwhiteside64]

I was hoping that someone could help identify the serial number or date code on this tag. From what I have gathered, the BN 64 means 1964 425 console shift:

http://www.tpocr.com/buicktc.html

Could the BN also means 3:07 rear end?

http://www.buickperformanceclub.com/switchpitch.htm

Any ideas?

Edited April 4, 2015 by dwhiteside64 (see edit history)

[RivNut]

I'm not going to make any assumptions based on code numbers. In '64 there wasn't a GS with the different valve body. So the code could be for the speedometer gears for a different rear end ratio, the gear selector to differentiate between a column and a floor shift, or a combination of both. The codes are similar for '65 but all ST400's had the switch pitch feature then. Here's another link for you to look at.

http://www.teambuick.com/reference/auto_400_codes.php

As you'll see, this link refers to different codes for different rear end ratios for the Riviera only, but only for '65 and '66. In '64, did every full size model Buick come with the 3.07 rear end? If not, then there are some missing pieces to the puzzle.

Ed

[Guest dwhiteside64]

I see what you mean Ed. I will keep searching and hope to find more clues to help solve the puzzle.

[JZRIV]

Interesting. Other than the GS non GS code differences for 65 and 66 I haven't seen a description of what if anything the two letter code represents other than the obvious. I'd guess it didn't have anything to do with the axle ratio. I am not sure about 64, but in 67 all Riv Trans were BT regardless of axle ratio.

If it didn't represent axle ratio then what was the production line indicator that directed which speedo gear was installed? Build sheet maybe?

Darren - I believe the 339 is a production sequence number. I haven't seen any documentation that can place certain relevance on this number other than being a general sequence reference during 64 production. On the 66 ST400 I found a cast in date code on top of the trans back by the tail shaft housing. This code tied directly to the build date of my car. Its in a recessed area that gets covered in grime.

[Guest dwhiteside64]

Thanks Jason for the added info. Besides the Riviera and Wildcat, were there any other models in 1964 that used the ST400 with a console shift? My car's production number is 9928 and was built during the 2nd week of December 1963. Wonder if the production sequence number corresponds at all to this date.???

Just from reading on different websites I believe the serial number may be 11101 but I'm not 100%. It also may be the speedo gear ratio. Hopefully someone else can tell us what they find on their transmission tag so we can compare numbers.

[sean1997]

The 1967 chassis service manual calls the 3-digit number a "day built code number". It is not a straight day number because there are values over 365. Some theories on how it may decode are:

1. Shift number starting from January 1st.

2. Day number over a 2-year cycle starting January 1st.

The last two digits of the model year combined with the last digit of the transmission code and the day built code form the production code number (CODE NO.) in the middle of the tag.

The transmission code combined with the last two digits of the model year and a sequential number form the transmission serial number (SERIAL NO.) stamped at the bottom of the tag. I've been told the sequential number starts at 1001 for each model year. I don't know that for sure, but regardless, it starts low and increases through out the model year.

I've attached some pictures of other transmission tags.

[sean1997]

Last group of pictures.

Edited April 6, 2015 by sean1997 (see edit history)

[Guest dwhiteside64]

Thank you Sean for the great pictures and your input. I found this website describing the TH400 tag breakdown:

http://chevellestuff.net/qd/th400.htm

So it looks like the date code is figured from the start of the calendar year in which the new model was introduced. For example the 1964 model, which came out during the summer of 1963, started from January 1st, 1963. That would mean that my tranny was built on December 5th 1963, very close to the build date of the car itself.

Edited April 6, 2015 by dwhiteside64 (see edit history)

[JZRIV]

Excellent info guys! Great posts.

[Guest dwhiteside64]

Thanks Jason. It's great how people keep adding information and the truth finally comes out

[JZRIV]

My 66 tag is number 442. Using the coding from the chevelle page that means its 365 days in 1965 + 77 days in in 1966 equaling 442 which puts it smack in the middle of March which matches up with many other dates codes on the car as well as the trans casting date stamp. Fisher tag body build date is 03E

No wonder I could never figure out this coding.

[Guest dwhiteside64]

Yeah Jason I'm sure it's nice to know that it's in all likelihood the original tranny. I looked for the VIN on the lower driver's side by the kickdown switch location but it wasn't there. Probably added sometime later in production because there are examples of this on the chevelle website.

[Alpha*Male]

So it's safe to say that this ST400 tag is out of a GS? It is out of a 65 Riviera. 

[Rivman]

Very well could be?

 

This is what mine looks like ...

 

 

Mine still has the paint showing but the stamped lettering does look the same as yours. What is the build date of your '65, and is it a GS?

 

The transmission tag you picture above was built on or about March 10th, so if the car was built shortly thereafter if could be correct for the vehicle? The build date of my '65 GS is 04B, the trani was built on or about March 29th, so my GS was built with-in about 2 weeks of the trani build date.

[RivNut]

And mine

[hermanangus]

Here’s mine. BQ code would  appear to be a correct and original for my 64 factory dual carb console shift.302 = Oct 29,1963. 

Edited November 21, 2018 by hermanangus (see edit history)

[RivNut]

From the reference library on Team Buick:

 

I only copied and pasted 64 - 66.  There's more if you want to look.

 

YEAR	APPLICATION	CODE
1964	300 V8 LeSabre	BU
	401 V8 column shift	BJ
	401 V8 console shift	BK
	425 V8 column shift	BL
	425 V8 one carb console shift	BN
	425 V8 two carb column shift	BP
	425 V8 two carb console shift	BQ
1965	300 V8 LeSabre	BU
	401 V8 3.07 axle	BJ
	401 V8 Riviera (3.23 axle)	BR
	425 V8 4bbl. carb 3.07 axle	BN
	425 V8 3.23 axle	BT
	425 V8 two carb 3.07 axle	BO
	425 V8 two carb Riviera (3.42 axle)	BS
1966	340 V8 LeSabre	BU
	401 V8	BR
	425 V8 Grand Sport & Riviera	BS
	425 V8 all others	BT

 

I don't claim this to be accurate, I'm only posting this because I knew what it was and where to find it.  If there are errors, IT"S NOT MY FAULT

Edited November 21, 2018 by RivNut (see edit history)

[JJ62]

I know this is an old post, but I have a couple of questions. I'm going to look at a '65 GS this weekend and would like to verify the BS code. Which side of the car is the transmission plate on? Is the easiest way to verify the positraction rearend by jacking the car up and spinning one wheel? And the other wheel should spin in the same direction?

[RivNut]

1 hour ago, JJ62 said:

I know this is an old post, but I have a couple of questions. I'm going to look at a '65 GS this weekend and would like to verify the BS code. Which side of the car is the transmission plate on? Is the easiest way to verify the positraction rearend by jacking the car up and spinning one wheel? And the other wheel should spin in the same direction?

The plate is on the passenger side.  There are multiple ways to determine if a car has posi trac.  A friend of mine has a Gran Sport with a peg leg 3.07 rear gear.  He didn't like the RPM's the engine turned while driving on the highway so he pulled his 3.42 posi. (Don't ask. He tossed it out. I know, I'm sick about it too. He doesn't even remember where it got tossed.)

 

Base most of your facts on matching VIN and Engine Serial numbers and the LX Production code,  and the BS transmission.